Navigation technologies are utilized in various fields such as guiding to a destination and presenting an operating procedure during an operation. The navigation technologies are to provide support for facilitating a certain action, and hence systems which allow understanding as intuitive as possible have been demanded hitherto. As one of such systems, there exists a navigation technology utilizing what is called an augmented reality which displays data of texts, images, and so on managed in a computer in a manner overlaid on a real environment, so as to give supplementary information to the real environment.
For example, as a navigation technology for shopping, there has been disclosed a technology utilizing augmented reality (hereinafter abbreviated AR) to perform three-dimensional navigation on a route to a target attraction or on display information of products recommended by a shop side in a theme park or a shopping mall (see, for example, Patent Literature 1). More specifically, it is a technology to calculate the position and posture of a mobile information terminal at a time of imaging, and use a marker shown on the image imaged by the mobile information terminal to display predetermined information, which is related to the marker in advance, in a manner overlaid on the imaged image. Note that the AR is a technology to display data of texts, figures, still images, moving images, and so on managed in a computer (hereinafter referred to as computer-graphics image data) in a manner overlaid on a real environment, so as to give supplementary information.
Further, there is known a technology such that products to buy are registered in a list in a mobile terminal in advance, and when the user walks near a product registered in the list, product information of this product is displayed on the mobile terminal (see, for example, Patent Literature 2).
Similarly, there have been developed several technologies for navigating to a vacant space in a parking lot. In a shopping center, amusement park, or large public parking lot, it is difficult for the driver of a car to comprehend where there is a vacant space, and hence guidance information is necessary. Accordingly, in certain parking lots, for example, sensors are provided in respective parking spaces for detecting parking statuses. Then, the parking lot is divided into plural blocks, and guidance of vacant space is given to the driver by displaying “full”, “vacant”, or the like in each block on an electric sign or the like.
However, even when “full”, “vacant” or the like is displayed at the entrance of each block, the driver is not able to comprehend the status of “full” or “vacant” unless he or she actually gets close to this block. Alternatively, there are also parking lots employing an electric sign listing information of the parking lot, but it is difficult for a driver to reach his/her target space by looking at the electric sign while driving. Further, one-way passages are often set in the parking lot, where there is a problem that even when the driver finds “vacant”, it is still difficult for the driver to reach a vacant parking space.
To solve such problems, for example, Patent Literature 3 disclosed a system to reflect vacant statuses of a parking lot on a car navigation system. The method of Prior Art Literature 1 detects a car which is about to leave a vacant space, and this situation is transmitted to a car navigation system of another car, thereby guiding a vacant space existing in the vicinity.
Similarly, in the field of ships, various navigation technologies have been developed. In operation of a ship, there is performed navigation with marine charts particularly in old days, or navigation utilizing a radar device, GPS, and/or the like nowadays. Incidentally, in the case of a ship cruising in a coastal area, the above-described equipment is fully used for avoiding any trouble related to obstacles below sea level, such as stranding on a reef. Also, not limited in coastal areas, not only visual observation but also information from equipment is utilized on the sea in order to avoid contacting with another ship due to dense fog or the like.
Although it is possible to increase avoidance of stranding or contacting with another ship by utilizing these devices, there is demanded a system which is capable of detecting and avoiding hazards more intuitively. For example, Non-Patent Literature disclosed a system which three-dimensionally displays an automatic identification system (AIS) and an electronic marine chart in combination. However, eventually, a shipman is required to understand a graph display as shown in FIG. 7 of Non-Patent Literature 1, and judge collision or the like.